Consumers and health professionals are advised that the TGA is investigating reports that glyceryl trinitrate (GTN) tablets, sold in Australia under the brand names Anginine and Lycinate, are taking longer than expected to dissolve under some patients' tongues, which may impact patient safety. Some reports have also indicated that the tablets are difficult to break in half.

GTN tablets, which are given under the tongue, are used to treat acute angina pectoris (chest pain caused by coronary heart disease).

The tablets are used in acute healthcare settings, such as hospitals and ambulances, but can also be used by patients at home.

Both Anginine and Lycinate share the same formulation, including the new formulation that is available in a circular tablet (the old formulation was a square tablet).

To date, the reports of longer than expected time to dissolve and difficulty breaking tablets in half have related only to the new formulation of GTN tablets. The TGA is working with the current sponsor, Arrow Pharmaceuticals and previous sponsor, Aspen Pharma, to investigate this issue.

If a GTN tablet does not dissolve properly or quickly enough, the patient may not receive adequate or timely therapy, which could lead to other serious health consequences.

The affected products are not being recalled at this time while the TGA continues to investigate the issue.

Please note that there is a spray-based formulation of GTN, marketed as Nitrolingual Pump Spray, and this product is not affected by this issue.

The TGA will continue to investigate this issue and will provide further information when it becomes available.

Information for consumers

If you or someone you care for uses Anginine or Lycinate tablets (GTN tablets), please be aware of this issue.

Do not stop taking your medicine if you need it. Continue taking your GTN tablets as directed by your health professional, allowing them to dissolve under the tongue. Be aware that they may take longer to dissolve than normally expected and may be difficult to break in half.

GTN tablets must not be swallowed like normal tablets, as they will not work.

Continue to store and handle your GTN tablets as directed on the label.

To date, this issue only appears to affect the new formulation of GTN tablets (circular tablets). There have been no reports of this issue relating to the old formulation (square tablets).

Drinking a mouthful of water before putting a GTN tablet under your tongue may help it to dissolve.

If you have any questions or concerns about this issue, speak to your health professional. They may be able to advise of alternative treatments.

The TGA is working with Arrow Pharmaceuticals and Aspen Pharma to investigate this issue. Further information will be provided when it becomes available.

Information for health professionals

If you are treating patients who use GTN tablets, particularly in a home setting, please advise them of this issue.

Advise them not to stop taking their medicine if they need it and reiterate the directions for use, storage and handling. Instruct them to seek urgent medical attention or call 000 if their chest pain continues.

If they are experiencing problems with the new formulation (circular tablet), drinking a mouthful of water before sublingual administration may help it to dissolve. However, ensure that they understand that they must not dissolve the tablet in water before taking it or swallow it like a normal tablet.

In acute healthcare settings, patients should be closely monitored when administering GTN tablets.

Reporting problems

The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medicine or vaccine.